As a turbo compressor that is applied to a turbo refrigerator and the like, there is known in the prior art one that is provided with a housing in which lubricating oil is housed, a large diameter gear as a gear member that is housed in this housing and by whose rotation lubricating oil is supplied, and a demister that is arranged above the large diameter gear in the housing, is provided with an intake port that is in communication with the outside of the housing, and which catches the lubricating oil kicked up by the rotation of the large diameter gear and returns it to the lower part of the housing (for example, refer to Patent Document 1).
In this kind of turbo compressor, the intake port of the demister is connected to a space with a lower pressure than the interior of the housing via a pressure equalizing tube, whereby an increase in pressure in the housing is inhibited. Also, in the housing, oil smoke is produced by the lubricating oil that is kicked up by the rotation of the gear member. For this reason, the demister, when suctioning in air in the housing from the intake port, prevents the lubricating oil from being discharged to the outside of the housing by catching the lubricating oil that is mixed in the air and returning it to the lower part of the housing.